Recently did fun research.

After PHP and few other components update on VPS, PM started to come slightly damaged.

Not on personal-view.com, but on nex-hack.info.

Further testing showed that same message sent to Outlook will look distored, and sent to gmail will look just fine.

It took some time to find relevant link - http://octeth.com/forum/showthread.php/5888-Email-output-with-php-5.3

One other - http://www.jeremytunnell.com/posts/really-hairy-problem-with-seemingly-random-crlf-and-spaces-inserted-in-emails

Just commenting three lines in phpmailer solved issue.

But isn't it weird?

So I looked in more details.

Check this phpmailer bug link (still open :-) ): http://sourceforge.net/tracker/?func=detail&aid=2792361&group_id=26031&atid=385707

In comments you'll find what build in phpmailer function responsible for quoted printable encoding, in fact, contain code to prevent appearence of long time Microsoft bug.

So, after developers of phpmailer realised that they can now use standard PHP function in new versions they forgot about it.

And why all had been ok on PV? It just did not used such encoding.

Right now it works on '8bit' setting fine, but it is recommended to use 'base64', as you could have long and international titles.